3 dimes are worth (a)   cents.

5+5=

(a)  

5+6=

(a)  

5+7=

(a)  

5+8=

(a)  

Explain how to solve 5+6=

7+7=

(a)  

7+8=

(a)  

7+9=

(a)  

7+10=

(a)